Presentation on theme: "Computer Skills Preparatory Year Presented by:"— Presentation transcript:
1Computer Skills Preparatory Year 2011-2012 Presented by: L.Obead Alhadreti
2< the death of Steve Jobs! > Last week - Lecture 1The definition of the computerThe history of computersThe types of computers< the death of Steve Jobs! >
3Lecture 2 - Outline The main parts of the Personal Computer Computer HardwareMemory MeasurementFactors that Impact on a Computer's Performance
4Main parts of the PC Hardware: Software Computers Have Two Main Parts: The term hardware refers to the physical componentsof your computer which you can physically touch or seesuch as your monitor, case, disk drives, microprocessor andother physical parts.SoftwareThe software is the instructions that makes the computer work.Software is held either on your computers hard disk, CD-ROM,DVD or on a floppy disk and is loaded from the disk intothe computers RAM, as and when required.
8Main parts of the PC Hardware: Hardware can be categorised into: Input Units, Output Units Central processing Unit, Memory Unit (main memory), and Storage devices (secondary memory).
9Main parts of the PC Input Units: Input units: those parts of the compute receivingdata to programs.The MouseA small hand-held device which has the shape of mouse.enhances user’s ability to input commands, manipulate text,images.
10Main parts of the PC The Keyboard The keyboard is still the commonest way of enteringinformation into a computer.Tracker Ballsan alternative to the traditional mouse and often used bygraphic designersScannersA scanner allows you to scan printed material andconvert it into a file format that may be used withinthe PC.
11Main parts of the PC Touch Pads A device that lays on the desktop and responds topressure.Light PensUsed to allow users to point to areas on a screen.JoysticksMany games require a joystick for the proper playing ofthe game.
12Main parts of the PC Output Units: Output Units: those parts of the computer that provideresults of computation to the person using thecomputer.Monitors:are the most commonly used output device. used foroutputting information in an understandable format forhumans.
13Main parts of the PC Printers There are many different types of printers: dot matrix,ink jet, and Laser. In large organizations laser printersare most commonly used due to the fact that they canprint very fast and give a very high quality outputPlottersA plotter is an output device similar to a printer, butnormally allows you to print larger images.
14Main parts of the PC Speakers Enhances the value of educational and presentation products.
15Main parts of the PC Central Processing Unit: the Central Processing Unit (CPU), also called a processor, or a microprocessor, is the brains within your computer. It performs the arithmetic and logical process within the computer.made up from a semiconductor, Silicon. contain hundreds of millions of transistors which areinterconnected through extremely fine wires made of copper.it determines how fast your computer will run.The speed (clock speed) of CPU measured by Hertz (MHz) and (GHz).measured by its Hertz speed (e.g. MHz, GHz). A processor with speed of 600 MHz is much faster than a processor with speed of 400 MHz.processor manufacturers: Intel, AMD, and Cyrix processor. CPU types: Intel Pentium, Intel Celeron, and AMD Athlon.
16Main parts of the PC The CPU consists of : Control Unit (CU): coordinates all activities of the computer by determining which operations to perform and in what order to carry them out.Arithmetic and Logical Unit (ALU): perform arithmetic operations (addition, subtraction, multiplication and division), and Logical operations (and, or, not, …) and to make some comparisons (less-than, equal, … etc.)Some Registers: where the data used by ALU are stored.enjoy watching:
17Main parts of the PC Memory Unit: RAM: The RAM (Random Access Memory) is where the operating system isloaded and also where your applications, such as word processor, arecopied. It saves the computer data temporarily while the program isrunning. It loses its contents if power is disconnected (volatile memory).ROM:The ROM (Read Only Memory)is a special chip heldon your computer's system (mother) board.It contains software that is required to make yourcomputer work with your operating system. It does not loseits contents by disconnection of power.
18Memory Measurement Bit All computers work on a binary numbering system, i.e. they process data in one's or zero's. This 1 or 0 level of storage is called a bit.ByteA byte consists of eight bits.KilobyteA kilobyte (KB) consists of 1024 bytes.MegabyteA megabyte (MB) consists of 1024 kilobytes.GigabyteA gigabyte (GB) consists of 1024 megabytes.
19Main parts of the PC Storage Devices: The internal Hard Disks: Internal hard disk are the main, large data storage area within yourcomputer. used to store your operating system, your applicationprograms (i.e. your word processor, games etc) and your data. They aremuch faster than CD-ROMs and floppy disks and can also hold muchmore data.The speed of a hard disk is often quoted as "average accesstime" speed, measured in milliseconds. The smaller thisnumber the faster the disk.Often in excess of 10 Gigabytes.
20Main parts of the PC The external Hard Disks: Normally slower that internal disks, but more expensive versions offerthe same performance as internal hard disks.Capacity: same as internal disks.Cost: More expensive than internal disks.
21Main parts of the PC Floppy Disk: They are very slow compared to hard disks or CD-ROMs, and hold relatively smallamounts of data (1.44 Mbytes). Unreliable.Zip Disk: Slower than normal hard disks but ideal for backups.Capacity: 100 or 250 Megabytes.
22Main parts of the PCJaz Disk: Slower than normal hard disks but idealfor backups. Capacity: around 2 Gigabytes.CD-ROM (Compact Disc Read-only memory)& DVDs (Digital Versatile Disc): Similar to the audio devicesfamiliar in home use but hold computer data ratherthan music. The storage capacity of CD reaches 750megabyte, whereas the storage capacity of the DVDreaches more than 4 gigabytes.
23Main parts of the PCPeripheral devices: A peripheral device is any device that you canattach to your computer.
24Factors That Impact on a Computer's Performance CPU speedRAM sizeHard disk speed and capacity
25Components of a Computer System Central Processing Unit (CPU)Datacontrol unit (CU)MemoryArithmeticlogicUnit (ALU)outputunitsRAMInputunitsROMsecondaryMemoryInformation/Knowledge
26Lecture 2 - Conclusion The main parts of the Personal Computer HardwareMemory MeasurementFactors That Impact on a Computer's Performance